QQmlXMLHttpRequest: optimize header()

Early out to avoid string conversion.

Change-Id: I533a5ec671087d887184b4e92d79f5ab9cc1e013
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 6 insertions, 5 deletions

diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index 0310d42fa4..85e17525a5 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -1146,11 +1146,12 @@ void QQmlXMLHttpRequest::addHeader(const QString &name, const QString &value)
 
 QString QQmlXMLHttpRequest::header(const QString &name) const
 {
-    QByteArray utfname = name.toLower().toUtf8();
-
-    for (const HeaderPair &header : m_headersList) {
-        if (header.first == utfname)
-            return QString::fromUtf8(header.second);
+    if (!m_headersList.isEmpty()) {
+        const QByteArray utfname = name.toLower().toUtf8();
+        for (const HeaderPair &header : m_headersList) {
+            if (header.first == utfname)
+                return QString::fromUtf8(header.second);
+        }
     }
     return QString();
 }